A comparative analysis of P2G/P2L-systems for the combined production of liquid and gaseous biofuels

P2G is an acronym for Power-to-gas, meaning that power is used to split water into hydrogen and oxygen by electrolysis. The hydrogen can either be used directly as the fuel or raw material it is, or be reacted further with carbon monoxide and/or carbon dioxide into a bio­fuel/biochemical, e.g. methane or methanol. When the end-product is a liquid, the technology is termed Power-to Liquid (P2L). Today, there is one commercial P2L plant on Iceland and around 40 pilot and/or demonstration P2G/P2L-plants in Europe, mostly located in Germany.

The purpose of this study is to identify, analyse and suggest different possibilities for P2G/P2L in Norrbotten with respect to the regional electricity market and hydrogen demands, having the bio­refinery infrastructure in Piteå as a starting point.

One of the conclusions from the analysis is that one should strive for to support all processes with hydrogen from a single electrolyzer (~1 MWe), possibly self-sustained by a local wind turbine (3-5 MWe). For cost reasons, pipelines for hydrogen distribution between the various inherent processes should be mini­mized, and the most mature electrolysis technology, the alkaline type (AEC), should be the choice of preference in a first stage of development. The considerably more efficient, but today less mature, high temperature SOEC technology could be used at a later stage for integration and provision with (residual) heat from the biorefinery.